Grenade launcher valve



MalCh 4, 1952 ,1. c. GARAND GRENADE LAUNCHER VALVE -r 2 SHEETS-SHEET lFiled Aug. `14, 194e Jahn Burn-nd.

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March 4, 1952 J. c. GARAND 2,587,611

GRENADE LAUNCHER VALVE: v Filed Aug. 14, 194e 2 SHEETS- SHEET 2 John. DGurus-La.

Patented Mar. 4, i952 UNITED STATES OFFICE GRENADE LAUNCHER VALVEApplication August 14, 1946', Serial No. 690,432

(Cl. 25'1a127) 2 Claims.

(Granted under the act of March amended April 30, 1928; 370 0.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment to me ofany royalty thereon.

The present invention relates to improvements in a valve mechanism forassociation in a grenade-launcher assembly which is especially designedfor attachment to the caliber .30 Ml U. S. rifle. l

That is to say, the features of this invention are incorporated in agrenade-launching attachment for a rearm of the gas-operated type and,as will be seen, the invention is especially directed to the provisionof a novel valve mechanism particularly adapted to reduce the pressureof the actuating gases on the recoiling members of such rearm.

As is well known, a grenade-launcher is customarily attached to themuzzle of the rearm and the grenade is discharged from the launchingdevice by ring a blank cartridge in such firearm. When the firearmemployed is of the gas-operated type, as is common, it is most desirablethat such firearm may be utilized for grenade launching without anymodification to the gas system. And, furthermore, in the usual case, theWeight of the grenade is many times heavier than that of a bulletnormally fired from the rearm so that in order to launch the grenade,the gases must necessarily maintain a high pressure within the barrelfor a much longer time than when firing a bullet.

During this period, a portion of the actuating gases are divertedVthrough the usual gas port in the barrel so as to impinge with anexcessively high and continuing pressure on the piston of the rearm. Asa result of this action, the piston and recoiling members of thegas-operated fire-- arm are driven rearwardly with violent force and ata velocity considerably greater than normal due to the tremendousacceleration given such parts by the excessive gas pressure with theconsequence that there is excessive breakage of these parts, even, toofrequently, of the receiver of the rearm.

There are already known to the art, launcher assemblies that can notonly be quickly and conveniently attached to the gun barrel of agasoperated weapon but which Will, through the very act oi attaching thelauncher, automatically open a, valve to permit the escape of gas fromthe gas cylinder to prevent application of excessive forces to therecoiling parts due to the greater duration of gas pressure duringgrenade launching` Obviously they proper operation of 3, 1883, as G.757) such valve in both its open and closed positions is an essentialrequirement, yet valves heretofore utilized have not successfullywithstood the severe temperatures andl stresses of such application.

Accordingly, it is a principal object of this invention to provide animproved valve mechanism for the gas system of agas-operated firearmwhich cooperates with a grenade launcher in such a way as to reduce thegas pressure on the recoiling members in order to prevent damage to suchmembers and to the rearm, in general, when a grenade is launched.

Also, it is well known that such valves-as are used in connection withgrenade-launching devices are necessarily subjected to high pressuresand temperatures. Most such valves embody springs for actuating purposeswhich, of course, deteriorate under high pressures and temperatures. Itis, therefore, a special feature of the construction of this inventionthat the use of springs is obviated.

It will be appreciated that such a valve as we arerr here concerned withmust positively open when the plunger of the assembled launcher moves`against it, while at the same time when the valve is in closed position,means must be provided to prevent its being jarred or shaken open. Inother words, it is desirable', for proper functioning, that the valvemust be forcibly lopened and as Will be seen the construction of thisinvention is so arranged. Yet the valve must close readily after thelauncher is removed.

The specic nature of the invention as well as other objects andadvantages thereof will clearly K appear from a description of apreferred embodiment as shown in the accompanying drawings in which:

Fig. l is a side elevational View, partly in section, of the muzzle endof a gas operated firearm incorporating a valve constructed inaccordance with the invention.

Fig. 2-is a front elevational View of the assembled gas cylinder lockscrew and valve.

Fig. 3i is a longitudinal sectional view of the assembled gas cylinderlock screw and. valve taken along the plane 3-3 of Fig. 2.

Fig. 4 is a sectional view of Fig. 3 taken on the plane A- thereof.

Fig. 5 is an elevational view of the valve member.

In Fig. 1, there is shown a conventional grel nade-launching device 6oassembled to the front end portionof a gas-operated rearm of the typesimilar tothe U. S'. riiie caliber .30, M1. A gas cylinder lil is shownmounted beneath, and

3 locked to, the end of the firearm barrel 2, as by a screw collar 5.

The usual gas port 6 is provided in the barrel and this is incommunication with a gas port 1 provided in the gas cylinder l so as toprovide a passage for the actuating gases to be admitted into the gascylinder whereby such gases may impinge on the face of a piston 9reciprocable within the gas cylinder. This piston 9 connects with theoperating parts of the rearm which are not shown.

The novel combination gas cylinder lock screw and valve assembly of thisinvention consists of a housing which is indicated generally by 20 andwhich is provided with an axial opening or bore 22, as shown in Fig. 3.This housing 20 includes a main body portion 24 which is insertablethrough collar 5, an enlarged head portion 26 on the forward endof bodyportion 24 and separated therefrom by a neck portion 28 of reduceddiameter, and an inner or rear end portion 23 which is threaded andcooperates with threads in the forward end of the gas cylinder as shown,Rear end portion 29 is also separated from the main body by a reduceddiameter neck portion 21.

The valve member 34 includes a forward spindle-like or stem portion 30and a rear coneshaped head portion 32. The stem portion 30 comprises asplit or expansible cylindrical member having spaced apart andsimilarly-shaped parts 42. The latter are formed by providing aninwardly-extending `cut-away 44 in the stem member and, as shown, thesaid parts 42 are integral with the head portion 32 so that the valveis, of course, a unitary member even though having an expansible stemportion.

The valve member is inserted into the rear end of bore 22 of the housing20 and the stem 30 is adapted to frictionally engage the interiorthereof. As shown, the rear the housing 20 is provided with a conicalvalve seat 46 substantially complemental with the cone shaped head 32,thereby providing a tight seal between the gas cylinder I and aplurality of slots or exhaust ports 62 when in the closed or forwardposition as will be later described more fully.

Within the central portion of the bore 22 of the housing 20 there isprovided an outwardly sloping conical surface 40. Likewise theextremities of the stem parts 42 of valve 34 are shaped so as to provideconical surfaces 43 complemental to the surface 44. Thus, as the valvemember 1s forcibly moved rearwardly relative to housing 20, the slopingsurfaces 4G and 43 engage one another with a cam-like action so that thesplit parts 42 of the expansible member are compressed together.

Corresponding side surfaces of the parts 42 are cut-away to providealigned and preferably correspondingly-shaped cut-outs I, as shown inthe drawings. Also, the housing 20 is provided with oppositely-disposedholes 52 therein which extend transversely with respect to thelongitudinal axis of the housing member and at the same time are incommunication with the cut-outs 5l. A pin or rod member 54 is disposedin the cut-outs 5| crosswise of the stem 30 of the valve and has itsopposite end portions engaged in holes 52 as shown. The rod member 54acts as a stop to limit the movement of the valve member in the housing20. That is to say, the rod 54 limits rearward movement of valve member34.

Spaced, longitudinally extending slots 62 are cut out of the peripheryof bore 22 of housing end of the bore of l 20 to provide exhaust portswhich communicate with the interior of. gas cylinder l0 when valvemember 34 is in its rearward or open position. Slots 62 also function asslots cooperating with an assembly tool.

In assembling the device, the parts 42 are squeezed together and thevalve stem 30 is inserted into bore 22. Pin 54 is then inserted in holes52 securing the valve member 34 in assembly in housing 20. The lockscrew is then ready to be screwed into assembly in the gas cylinder l0.

When a grenade launcher 60 is mounted on the rie, a projecting stud-likepart or plunger member 6l on the mounting bracket 63 is arranged tocontact the forward surface of the valve stem 30. As the grenadelauncher 60 is assembled to the rifle, the plunger 6l projects into bore22 of lock screw 20 to engage the forward ends of the parts 42, and thusthe valve head 32 is forcibly moved rearwardly relative to the housingso as to provide communication ,between the interior of gas cylinder I0and ex haust ports E2 of the housing.

In this condition, a substantial quantity of the actuating gases arediverted through the ports in the valve so as to escape to theatmosphere and thereby render the gas pressure force on the pistonpractically inoperative. When the grenade launcher 6U is removed fromthe muzzle of the firearm, the valve is readily closed by theapplication of any suitable force thereon.

It will thus be also seen that the accidental displacement of the valvemember in the lockscrew body member is resisted by the frictionalengagement between the prongs 42 and the interior of the bore 22, sothat the valve 34 will remain in its closed position until forciblyopened by assembly of a grenade launcher on the rifle.

1 claim:

1. A valve mechanism for a grenade launcher, comprising a valve housing,said housing being provided with an axial bore therethrough having aconical counterbore on one end thereof, said housing being provided withoppositely disposed aligned openings which extend transversely thereofand lead into said axial bore, a valve member movably mounted in saidhousing, said valve member including a head portion constructed toengage said conical counterbore and a split expansible stem portionwhich projects from said head portion and extends into the bore of saidhousing, said stem portion being provided with a flattened surface, saidhousing and said stem portion being provided with cooperating camsurfaces arranged to resiliently urge said valve member inwardlyrelative to said housing and thereby yieldingly hold said head portionof said valve member on said conical counterbore of said housing, and apin member having its opposite end portions disposed in said openingsand the center portion engaging said flattened surface of said stemportion whereby movement of said valve member away from said counterboreis limited. y

2. A valve mechanism for a grenade launcher, comprising a valve housing,said housing having an axial bore in one end thereof terminating in aconical counterbore and a larger axial bore in the other end thereofwith a tapered bore connecting said bore and said larger bore, saidhousing being provided with oppositely disposed aligned openings whichextend transversely thereof and lead into said axial bore, a valvemember movably mounted in said housing, said valve member including ahead portion constructed to engage said conical counterbore and a stemportion which projects from said head portion into said bore of saidhousing and terminating in a tapered head portion constructed to engagesaid tapered bore, said stem portion being provided with a fiattenedsurface intermediate of said head portion and said tapered head portion,said stern portion consisting of a spiit rod-like part which iscontraetable when said tapered head portion is moved along said taperedbore of said housing and expansible to engage said tapered bore to Cainsaid valve member into said housing and thereby yieldingly hold saidhead portion of said valve member on said conical counterbore of saidhousing, and a pin member having its opposite end portions disposed insaid openings and the center portion engaging said attened surface ofsaid stem yportion whereby movement of said valve member away from saidcounterbore is imited.

JOHN C. GARAND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 548,835 Lafferty Oct. 29, 1895645,722 Holmes Mar. 20, 1900 852,334 Lewis Apr. 30, 1907 1,753,631Walters Apr. 8, 1930 1,800,173 Anderson Apr. 7, 1931 1,997,116 NielsenApr. 9, 1935 2,079,647 Abegg May 11, 1937 2,310,902 Voelkel Feb. 9, 19432,390,738 Rutherford Dec. 11, 1945 2,402,060 Luster June 11, 19462,416,287 Coates Feb. 25, 1947 2,455,361 Garand Dec. 7, 1948

